Projection Surfaces Detection and Image Correction for Mobile Robots in HRI

Projectors have become a widespread tool to share information in human-robot interaction with large groups of people in a comfortable way. finding a suitable vertical surface becomes a problem when the projector changes positions when a mobile robot is looking for suitable surfaces to project. two problems must be addressed to achieve a correct undistorted image: (i) finding the biggest suitable surface free from obstacles and (ii) adapting the output image to correct the distortion due to the angle between the robot and a nonorthogonal surface. we propose a ransac-based method that detects a vertical plane inside a point cloud. then,inside this plane,we apply a rectangle-fitting algorithm over the region in which the projector can work. finally,the algorithm checks the surface looking for imperfections and occlusions and transforms the original image using a homography matrix to display it over the area detected. the proposed solution can detect projection areas in real-time using a single kinect camera,which makes it suitable for applications where a robot interacts with other people in unknown environments. our projection surfaces detector and the image correction module allow a mobile robot to find the right surface and display images without deformation,improving its ability to interact with people. © 2017 enrique fernández-rodicio et al.